Backhoe boom lock

ABSTRACT

A backhoe is releasably locked to its support by pivotal movement of the backhoe to its transport position and is unlocked by manipulation of the earth working tool ram carried by the boom. The releasable lock consists of a pin carried by either the boom or the support, and a lug having a recess and inclined camming surface for guiding the pin into the recess. Either the pin or the lug is normally biased to a first position and is movable from the first position by interengagement between the pin and the camming surface when the boom is moved to its transport position to locate the pin in the recess and lock the boom to the support. By proper manipulation of the fluid ram associated with the earth working tool, the pin and recess are separated to allow the boom to be pivoted from the transport position.

United States Paten Shumaker et a1.

[451 May 21,1974- BACKHOE BOOM LOCK Inventors: John F. Shumaker, Mount Pleasant;

James O. Morehouse, Burlington, both of Iowa Feb. 4, 1972 US. Cl. 214/138, 214/130 Int. Cl B66f 9/00 Field of Search 214/517, 138 R, 138 C,.

References Cited UNITED STATES PATENTS 4/1968 Long 214/138 8/1946 Mandt.... 214/671 3/1935 Glaser 292/283 6/1972 Gauchet 21 /138 R Primary ExaminerRobert J Spar Assistant Examiner-.1ohn Mannix Attorney, Agent, or Firm'Dressler, Goldsmith, Clement & Gordon 5 7 ABSTRACT A backhoe is releasably locked to its support by pivotal movement of the backhoe to its transport position and is unlocked manipulation of the earth working tool ram carried by the boom. The releasable lock consists of a pin carried by either the boom or the support, and a lug having a recess and inclined camming surface for guiding the pin into the recess. Either the pin or the lug is normally biased to a first position and is movable from the first position by interengagement between the pin and the camming surface when the boom is moved to its transport position to locate the pin in the recess and lock the boom' to the support. By proper manipulation of the fluid ram associated with the earth working tool, the pin and recess are separated to allow the boom to be pivoted from the transport position;

11 Claims, 11 Drawing Figures PATENTEBmm m4 3811.582

SHEEI 1 BF 3 FIG. 2 FIG. 3

PATENTED HAY 2 1 I874 SHEET 2 BF 3 FIG. 5

PATENTED MAY 2 1 i974 SHEET 3 BF 3 BACKHOE BOOM LOCK BACKROUND OF THE INVENTION Such a backhoe and manner of holding the backhoe in a transport position is generally disclosed in Long et al., US. Pat. No. 3,376,984. In this patent, the boom is swung to a transport position that is generally vertical and slightly forward of a vertical plane extending through the pivot axis for the boom on the support. The boom is held locked in the transport position by the boom fluid ram which has gone over center. While this arrangement has found a considerable degree of commercial success, there are times when it is desirable to positively interlock the boom and its support without relying upon the fluid in the boom rams.

When a positive interlock is desired, it has been customary to provide the positive interlock between the boom and its support with one or more pins that are inserted through aligned openings in the boom and support after the boom has been located in the transport position. While the pins insure a positive interlock, there are several problems that result in consuming time of the operator and also are annoying to the operator. With the pin-opening arrangement, it is necessary for the operator to accurately position the boom in the transport position then leave the operators station to insert and secure the pins in the openings. If the openings are not aligned, it requires the operator to return to the operators station and manipulate the boom to re-position the openings. This sometimes becomes rather difficult since it is not readily ascertainable from the operators station when the openings are properly aligned.

Another problem encountered with the pin-opening arrangement is that the pins or bolts must necessarily Y be stored during normal operation of the working implement and can readily be misplaced resulting in lost time while the operator is looking for the bolts.

SUMMARY OF THE INVENTION According to the present invention, the boom is positively locked in a predetermined angular or transport position by properly positioning the earth working tool fluid ram relative to the boom and then pivoting the boom to its transport position. In moving to the transport position, releasable lock means automatically lock the boom to the support. To release the boom, it is only necessary to manipulate the earth working tool fluid ram to separate the interlocked elements. All of this can be accomplished by manipulation of control valves while the operator remains at the operators station thereby considerably reducing the time required to lock and unlock the boom from its support.

The releasable interlock means consists of a first element that is carried by the boom and a second element that is carried by the support with mounting means normally maintaining one of the elements in a first position and accomodating movement from the first position. One of the elements has a recess and a camming surface for guiding the other element into the recess during pivotal movement of the boom to the transport position. The elements are separated by actuating the implement or tool ram to cause the tool ram to pivot about its axis on the boom and separate the two elements thereby allowing the boom to again be pivoted from the transport position.

In one embodiment, the movable element consists of a pin and the mounting means include a pair of ears that are fixedly secured to the cylinder of the implement fluid ram and have slots for receiving the pin. The pin is normally maintained in a first or fixed position by a spring cooperating with the pin. The other element consists of a lug that is fixed to the support and has a recess for receiving the pin with an inclined camming surface that guides the pin into the recess.

In the alternateembodiment, the fixed element con sists of a pin fixed to the boom and the other element consists of a lug defined by a pair of arms pivoted on the support and each having a recess with an inclined camming surface on each arm for guiding the pins into the recess. A cradle is fixedly secured to the arms and is located in the path of pivotal movement of the implement ram and the lug defined by the arms and the eradle is biased to a first position by a spring.

In both embodiments, actuation of the ram to tilt the tool associated with the boom; which is normally accomplished by retraction of the piston into the cylinder, will cause the fluid ram to pivot away from the boom and release the interlock between the two elements.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF DRAWINGS FIG. 4 is an enlarged side view of certain portions of the boom and support showing the releasable lock means;

FIG. 5 is a view similar to FIG. 4 showing the releasable lock means in its locked position;

FIG. 6 is a view similar to FIG. 5 showing a position of elements immediately after being released;

FIG. 7 is a fragmentary prospective view of a portion of the implement and its support showing the releasable lock means in its separated condition;

FIG. 8 is a fragmentary side elevation of the implement showing a slightly modified releasable interlock;

FIG. 9 is a view similar to FIG. 8 showing the boom in a locked position on the support;

FIG. 10 is a view similar to FIG. 9 showing the position of the elements at the time they are separated from each other; and

FIG. 11 is a fragmentary prospective view of a portion of the interlock shown in FIGS. 8-10.

, DETAILED DESCRIPTION While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail two embodiments, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated.

FIG. 1 of the drawings shows a vehicle, generally designated by the reference numeral 10, having an earth working implement 12 supported thereon. The implement 12 consists of a backhoe which includes a frame 14 having Outriggers 16 supported thereon with the frame being attached to the end of the vehicle, adjacent and operators station 18. The operators station 18 may be part of the vehicle or may be the separate area on the frame 14.

A swing tower or support 20 is pivoted about a vertical axis defined by pins 22 on the frame 14 while a boom 24 is supported on its inner end by a pivot pin 26 on the support or swing tower 20. The boom is pivoted on the pivot pin 26 by a pair of fluid rams (only one being shown) located on opposite sides of the boom with the cylinder 30 of the ram secured to the support and the piston rod 32 secured to the boom. The earth working tool or dipper stick assembly 34 is supported on the outer end of the boom and consists of a member 36 pivoted intermediate its end on the free end of from 24 and movement of the member is controlled by a tool or second fluid ram 40. The tool or second fluid ram 40 has one end of its cylinder 42 pivotally supported at 44 on the boom adjacent the support 20 while the piston rod 46 is pivotally supported on one end of the member or dipper stick 36 by a pin 48. A bucket 50 is pivoted on the opposite or outer end of the dipper stick 36 by a further fluid ram 52 During normal operation of the implement or earth working, the boom is maintained on one side of a vertical plane extending through the pivot axis 26 and is moved from the raised position shown in FIG. 1 to any other position for the desired earth working operation. Also, the dipper stick and bucket are manipulated by applying pressurized fluid to opposite ends of the fluid rams 40 and 52, in the manner that is well known in the art and need not be described in detail.

As is discussed in more detail in the above mentioned Long et al. Patent, when it is desired to move the implement to its transport position, the fluid rams 28 are manipulated in such a manner that the boom is moved to the opposite side of the vertical plane extending through pivot pin 26. This manner of moving the boom to the transport position is explained in more detail in the Long et al. Patent, which is incorporated herein by reference.

According-to the present invention, the boom and its support curry releasable lock means that automatically interlock the boom and the support when the boom is moved to the transport position and the tool fluid ram is in a predetermined angular position with respect to the boom. The details of the releasable lock means are shown in FIGS. 47 wherein a lug or first element 60 is carried upon the support and a pin or second element 62 is carried on the boom. The lug has a recess 64 and an inclined camming surface 66 for guiding the pin or other element into the recess, as will be explained later.

The releasable locking means further includes mounting means 70 for mounting one of the elements. The mounting means includes support means for the element as well as biasing means for normally maintaining the element in one position and accommodating movement from that position. As more clearly shown in FlGS. 4 and 7, the mounting means consist of a pair of ears 72 that extend from the cylinder 42 and have elongated slots 74 defined therein. The elongated slots support the pin 62 for sliding movement along a path between first and second positions. The pin is normally held in the first position by a spring 76 that has one end attached to the cylinder through a clamp 78 and the oppsite end connected to the pin through a clevis 86. Thus, the bias of the spring will normally maintain the pin 62 at one end of the respective slots but will accommodate movement along the slots, as will be explained hereinafter.

When it is desired to lock the boom in the transport position, it is only necessary for the operator to manipulate the control valve (not shown) and extend the fluid ram 40 to the position shown in FIG. 1 wherein the bucket 50 is located in close proximity to the boom. The boom isthen swung towards the operators station by proper manipulation of the fluid rams 28 as is explained in the Long et al. patent. During such movement, the pin 62 engages the inclined camming surface and the angular position of the camming surface will cause the pin to move along the elongated slots 74 and ultimately be forced into the recess 64 by the spring 76, as is shown in FIG. 5. The force of the spring 76 will force the pin 62 into the recess when proper alignment has been reached and will also maintain the pin in the recess to provide the positive interlock between the boom and the support in the transport position.

When it is desired to release the interlock, it is only necessary for the operator to again actuate an appropriate control valve (not shown) and pivot the dipper stick assembly from the position shown in FIG. 2 to the position shown in FIG. 3. Because the member or dipper stick 36 is pivoted intermediate its end on the boom 24, this pivotal movement of the dipper stick assembly will simultaneously cause the cylinder 42 of the fluid ram 40 to pivot away from the boom about its pivot pin 44 carrying with it the two ears 72 and the pin 62. The pivotal movement of the cylinder 42 will cause the pin to be rotated about an axis, defined by pivot pin 44, a

sufficient amount to separate the pin 62 from the recess in the lug 60 and allow free pivotal movement of the boom relative to the support by appropriate actuation of the boom fluid ram.

It will be appreciated that the position of the elements 60 and 62 can be reversed and that the spring biased element may be carried by the support 20 rather than by the ram 40 which may be considered part of the boom.

A slightly modified form of the invention is shown in FIGS. 8-11 wherein the movable element of the locking means is carried by the support and the fixed eit: ment is carried by the boom. The appropriate parts, with the exception of the releasable lock means, have been identified by like reference numerals with the surf fix a added thereto.

The releasable lock means shown in FIGS. #5 l consists of a first element or lug that is pivotally mounted on the support 200 and a second element or pin 102 carried by the boom 24a. The first element consists of a shaft 103 (FIG. 11) supported for rotation on the support 20a and having a pair of arms 104 secured thereto and pivoted therewith. The outer ends of the arms each have a recess l06-and an inclined camming surface 108 similar to the arrangement discussed above. The arms and shaft are located between spaced side plates 110 that form part of the support a.

The arms also have a pair of abutments 112 fixed thereto and biased into engagement with the upper edges of the side plates 110 by a spring 114. The two arms 104 that broadly may be termed a lug, have an arm or cradle 116 extending therefrom and located in the pivotal path of movement for the second or tool fluid ram 40a.

The pin 102 consists of first and second pin segments respectively fixedly secured to the opposite sides of the boom. The pin segments are positioned such that pivotal movement of the boom to its transport position, while the abutments 112 are in engagement with the supports, will cause the lug or first element 100 to pivot upwardly and have the pin segment ride along the inclined camming surface 108 and ultimately be located in alignment with the recess at which time the spring 114 pulls the lug downwardly to interlock the boom and the support. This occurs when the fluid ram 40a is in its fully extended position shown in FIG. 2 and the final interlocked position between the two elements 100 and 102 is shown in FIG. 9.

When it is desired to release the boom from the support, the dipper stick assembly and more specifically the member 36 is pivoted from the position shown in FIG. 2 to that shown in FIG. 3 during which time the fluid ram 40a is pivoted about pivot pin 44a from the position shown in FIG. 9 to that shown in FIG. 10. During this pivotal movement away from the boom, the cradle, being located in the path of movement of the ram, pivots the arms 104 and shaft 103 to the position shown in FIG. 10. In this position, the boom can again be moved to its operative position.

The method of controlling the angular position of the boom relative to the support thus includes the steps of pivoting the boom on the support to a predetermined angular position or the transport position to automatically produce an interlock between the boom and support and thereby maintain the boom at the transport position and producing relative movement between the piston rod and cylinder assembly or elements of the fluid ram that pivots the dipper stick assembly on the support to release the interlock and allow the boom to be pivoted to different angular positions.

I claim:

1. In an earth working implement having one end of a boom pivoted on a support by a boom fluid ram, a member pivoted intermediate its ends on the free end of the boom by a second fluid ram having one ram element connected to said member on one end thereof and another ram element pivoted on the boom adjacent said support, said member being dimensioned and said second fluid ram being positioned so that extensionand retraction of said second fluid ram will cause it to pivot about its pivot on said boom and releasable lock means between said support and boom, said lock means comprising a pin carried by one of said support and boom; a lug carried by the other of said support and boom, said lug having a recess and an inclined camming surface for guiding said pin toward said recess; and mounting means for one of said pin and lug, said mounting means including biasing means normally maintaining said one of said pin and lug in one position and accommodating movement from said position, said pin, lug, boom and second fluid ram being positioned so that (l) pivotal movement of said boom to a transport position while said second fluid ram is in a first position will cause said pin to move along said inclined camming surface into said recess to lock said boom on said support and (2) relative movement of said ram elements of said second fluid ram causes pivotal movement of the latter which in turn will release said pin from said recess so as to release the boom for pivotal movement.

2. An earth working implement as defined in claim 1, in which said lug is fixed on said support and said mounting means includes mechanism fixed to said second'ram and defining a path of movement for said pin with said biasing means normally maintaining said pin a fixed position along said path.

3. An earth working implement as defined in claim 1, in which said pin is fixed on said boom and said mounting means includes a shaft supporting said lug" for pivotal movement.

4. An earth working implement as defined in claim 3, in which said lug further includes a cradle extending therefrom and located in the path of pivotal movement for said ram.

5. An earth working implement as defined in claim 1, in which said mounting means includes a shaft rotatable on said support and said lug includes a pair of arms secured to said shaft with a recess and inclined camming surface on the free end of each arm and a cradle extending from said arms and located in the path of said ram to pivot said anns, said arms having projections engaging fixed stops on said support to define said one position; and in which said pin is fixed to said boom.

6. An earth working implement as defined in claim 1, in which said first element is fixed on said boom and said second element is pivotally carried by said support, further including a cradle extending from said second element and located in the path of movement of said ram during extension and retraction thereof when said boom is in a transport position, one of said elements having a recess for receiving the other element and an inclined camming surface for guiding the other element into said recess so that (l) pivotal movement of said boom on said support to said transport position with said ram in a predetermined angular position on said boom will cause said other element to move into said recess to lock said boom on said support and (2) pivotal movement of said ram on said boom will release said elements and allow said boom to be pivoted from said transport position.

7. An earth working implement as defined in claim 6, in which said one element includes pin segments extending from opposite sides of said boom arid said other element includes arms pivoted about a fixed pivot axis on said support and each having a recess and'camming surface for the respective pin segments, said arms extending on opposite sides of said boom when said boom is in the transport position.

8. An earth working implement as defined in claim 7, further including abutments on said arms engaging said support and biasing means normally maintaining said abutments in engagement with said support.

9. In an earth working implement having one end of a boom pivoted on a support by a boom fluid ram, a member pivoted intermediate its ends on the free end of the boom by a second fluid ram having one ram element connected to said member on one end thereof and another ram element pivoted on the boom adjacent said support, said member being dimensioned and said second fluid ram being positioned so that extension and retraction of said second fluid ram will cause it to pivot about its pivot on said boom and releasable lock means between said support and boom, said lock means comprising a pin; a pair of spaced ears on said ram and each having a slot receiving said pin; a lug carried by said boom, said lug having a recess and an inclined camming surface for guiding said pin toward said recess; and biasing means normally maintaining said pin in one position at one end of said slots and accommodating movement from said position, said pin, lug, boom and second fluid ram being positioned so that (1) pivotal movement of said boom to a transport position while said second fluid ram is in a first position will cause said pin to move along said inclined camming surface into said recess to lock said boom on said support and (2) relative movement of said ram elements of said second fluid ram will release said pin from said recess.

10. An earth working implement as defined in claim 9, in which said lug is fixed to said support and is movable between said ears when saidboom is located in said transport position.

11. In an earth working implement having a boom end of said boom by a ram having a cylinder pivoted on the boom and a piston rod pivoted on one end of said member so that extension and retraction of said piston rod to move said member will cause said cylinder to pivot on said boom, releasable lock means between said support and said boom, said releasable lock means including a first element carried by said boom; a second element carried by said support; mounting means on said boom and including a pair of spaced ears each having a slot for receiving said first element; and biasing means normally maintaining said first element in one end of said slots to define a first position, said second element having a recess and a camming surface for guiding said first element into said recess during pivotal movement of said boom to a transport position while said cylinder is at a predetermined angular position on said boom to interlock said elements and thereby lock said boom to said support, said elements being arranged so that movement of said cylinder from said predetermined angular position on said boom will release the interlock between said elements. 

1. In an earth working implement having one end of a boom pivoted on a support by a boom fluid ram, a member pivoted intermediate its ends on the free end of the boom by a second fluid ram having one ram element connected to said member on one end thereof and another ram element pivoted on the boom adjacent said support, said member being dimensioned and said second fluid ram being positioned so that extension and retraction of said second fluid ram will cause it to pivot about its pivot on said boom and releasable lock means between said support and boom, said lock means comprising a pin carried by one of said support and boom; a lug carried by the other of said support and boom, said lug having a recess and an inclined camming surface for guiding said pin toward said recess; and mounting means for one of said pin and lug, said mounting means including biasing means normally maintaining said one of said pin and lug in one position and accommodating movement from said position, said pin, lug, boom and second fluid ram being positioned so that (1) pivotal movement of said boom to a transport position while said second fluid ram is in a first position will cause said pin to move along said inclined camming surface into said recess to lock said boom on said support and (2) relative movement of said ram elements of said second fluid ram causes pivotal movement of the latter which in turn will release said pin from said recess so as to release the boom for pivotal movement.
 2. An earth working implement as defined in claim 1, in which said lug is fixed on said support and said mounting means includes mechanism fixed to said second ram and defining a path of movement for said pin with said biasing means normally maintaining said pin a fixed position along said path.
 3. An earth working implement as defined in claim 1, in which said pin is fixed on said boom and said mounting means includes a shaft supporting said lug for pivotal movement.
 4. An earth working implement as defined in claim 3, in which said lug further includes a cradle extending therefrom and located in the path of pivotal movement for said ram.
 5. An earth working implement as defined in claim 1, in which said mounting means includes a shaft rotatable on said support and said lug includes a pair of arms secured to said shaft with a recess and inclined camming surface on the free end of each arm and a cradle extending from said arms and located in the path of said ram to pivot said arms, said arms having projections engaging fixed stops on said support to define said one position; and in which said pin is fixed to said boom.
 6. An earth working implement as defined in claim 1, in which said first element is fixed on said boom and said second element is pivotally carried by said support, further including a cradle extending from said second element and located in the path of movement of said ram during extension and retrAction thereof when said boom is in a transport position, one of said elements having a recess for receiving the other element and an inclined camming surface for guiding the other element into said recess so that (1) pivotal movement of said boom on said support to said transport position with said ram in a predetermined angular position on said boom will cause said other element to move into said recess to lock said boom on said support and (2) pivotal movement of said ram on said boom will release said elements and allow said boom to be pivoted from said transport position.
 7. An earth working implement as defined in claim 6, in which said one element includes pin segments extending from opposite sides of said boom and said other element includes arms pivoted about a fixed pivot axis on said support and each having a recess and camming surface for the respective pin segments, said arms extending on opposite sides of said boom when said boom is in the transport position.
 8. An earth working implement as defined in claim 7, further including abutments on said arms engaging said support and biasing means normally maintaining said abutments in engagement with said support.
 9. In an earth working implement having one end of a boom pivoted on a support by a boom fluid ram, a member pivoted intermediate its ends on the free end of the boom by a second fluid ram having one ram element connected to said member on one end thereof and another ram element pivoted on the boom adjacent said support, said member being dimensioned and said second fluid ram being positioned so that extension and retraction of said second fluid ram will cause it to pivot about its pivot on said boom and releasable lock means between said support and boom, said lock means comprising a pin; a pair of spaced ears on said ram and each having a slot receiving said pin; a lug carried by said boom, said lug having a recess and an inclined camming surface for guiding said pin toward said recess; and biasing means normally maintaining said pin in one position at one end of said slots and accommodating movement from said position, said pin, lug, boom and second fluid ram being positioned so that (1) pivotal movement of said boom to a transport position while said second fluid ram is in a first position will cause said pin to move along said inclined camming surface into said recess to lock said boom on said support and (2) relative movement of said ram elements of said second fluid ram will release said pin from said recess.
 10. An earth working implement as defined in claim 9, in which said lug is fixed to said support and is movable between said ears when said boom is located in said transport position.
 11. In an earth working implement having a boom pivoted on a support and a member pivoted on the free end of said boom by a ram having a cylinder pivoted on the boom and a piston rod pivoted on one end of said member so that extension and retraction of said piston rod to move said member will cause said cylinder to pivot on said boom, releasable lock means between said support and said boom, said releasable lock means including a first element carried by said boom; a second element carried by said support; mounting means on said boom and including a pair of spaced ears each having a slot for receiving said first element; and biasing means normally maintaining said first element in one end of said slots to define a first position, said second element having a recess and a camming surface for guiding said first element into said recess during pivotal movement of said boom to a transport position while said cylinder is at a predetermined angular position on said boom to interlock said elements and thereby lock said boom to said support, said elements being arranged so that movement of said cylinder from said predetermined angular position on said boom will release the interlock between said elements. 